Pregnant guinea pigs were exposed to tape recorded textile mill (weaving room) noise at 115 dB Sound Pressure Level, for 8 hours/day, 5 days a week. Exposure generally began at the third trimester of pregnancy, but varied due to discrepancies between the estimated breeding date and the actual breeding date as determined by delivery. The hearing levels of offspring were measured and compared with that of offspring from otherwise identical mothers. Brainstem evoked responses recorded from chronically implanted scalp electrodes showed deterioration in the hearing of the offspring from exposed mothers. These differences appear significant at the p less than .01 level.